FWIW, I see at least some GNU-isms in the hwloc code that might be
problematic for embedding hwloc in other code bases that don't use gcc
to compile. E.g., in OMPI, we'd prefer to use the same compiler suite
to compile hwloc that was used to compile OMPI itself (e.g., intel,
PGI, ...etc. -- configuring/building hwloc with icc results in a *lot*
of warnings; I didn't test functionality).

I don't know if we want to target that for v0.9.1 or not -- my first
reaction is to postpone this to v1.0 in order to get v0.9.1 out the
door. Fully bake in all the embedding -- including cleaning up any
potential GNU-isms -- for v1.0.